The simple idea
Core features:
- Excessive daytime sleepiness — a constant struggle to stay awake.
- Sleep attacks — suddenly falling asleep.
- Cataplexy (the classic clue) — a sudden, brief loss of muscle tone triggered by strong emotion. Someone laughs hard and their knees buckle — while staying conscious.
- Sleep paralysis — briefly unable to move while falling asleep or waking.
- Sleep‑transition hallucinations — vivid images while falling asleep (hypnagogic) or waking (hypnopompic).
| Feature | What it is |
|---|---|
| Excessive daytime sleepiness | constant struggle to stay awake |
| Sleep attacks | suddenly falling asleep |
| Cataplexy | emotion‑triggered muscle weakness (stays conscious) |
| Sleep paralysis | briefly can't move on waking / falling asleep |
| Sleep‑transition hallucinations | vivid images falling asleep / waking |
A beautiful link back to Concept 11
"I saw someone in my room as I was falling asleep." Don't jump to psychosis! Ask: did it happen during a sleep transition? If yes, it's likely a normal‑ish sleep‑related hallucination — not a psychotic symptom. This is exactly why phenomenology (describing the experience carefully) matters.
Quick check ✅
- What is cataplexy, and what triggers it?
- Why doesn't a hallucination while falling asleep automatically mean psychosis?
Remember this 🌟
Where we're going next → One more sleep‑disturber, easy to mix up with a medication side‑effect — Concept 39.